Adrenocortical carcinoma may present differently in children and adults. Most tumors in children are functional, and virilization is by far the most common presenting symptom, followed by Cushing's syndrome and precocious puberty. Among adults presenting with hormonal syndromes, Cushing's syndrome alone is most common, followed by mixed Cushing's and virilization (glucocorticoid and androgen overproduction). Feminization and Conn syndrome (mineralocorticoid excess) occur in less than 10% of cases. Rarely, pheochromocytoma-like hypersecretion of catecholamines has been reported in adrenocortical cancers. Non-functional tumors (about 40%, authorities vary) usually present with abdominal or flank pain, varicocele and renal vein thrombosis or they may be asymptomatic and detected incidentally.

All patients with suspected adrenocortical carcinoma should be carefully evaluated for signs and symptoms of hormonal syndromes. For Cushing's syndrome (glucocorticoid excess) these include weight gain, muscle wasting, purple lines on the abdomen, a fatty "buffalo hump" on the neck, a "moonlike" face, and thinning, fragile skin. Virilism (androgen excess) is most obvious in women, and may produce excess facial and body hair, acne, enlargement of the clitoris, deepening of the voice, coarsening of facial features, cessation of menstruation. Conn syndrome (mineralcorticoid excess) is marked by high blood pressure which can result in headache and hypokalemia (low serum potassium, which can in turn produce muscle weakness, confusion, and palpitations) low plasma renin activity, and high serum aldosterone. Feminization (estrogen excess) is most readily noted in men, and includes breast enlargement, decreased libido and impotence.

The most common clinical features of MEN2B are:

Unlike Marfan syndrome, the cardiovascular system and the lens of the eye are unaffected.Mucosal neuromas are the most consistent and distinctive feature, appearing in 100% of patients. Usually there are numerous yellowish-white, sessile, painless nodules on the lips or tongue, with deeper lesions having normal coloration. There may be enough neuromas in the body of the lips to produce enlargement and a "blubbery lip" appearance. Similar nodules may be seen on the sclera and eyelids.

Histologically, neuromata contain a characteristic adventitious plaque of tissue composed of hyperplastic, interlacing bands of Schwann cells and myelinated fibers overlay the posterior columns of the spinal cord. Mucosal neuromas are made up of nerve cells, often with thickened perineurium, intertwined with one another in a plexiform pattern. This tortuous pattern of nerves is seen within a background of loose endoneurium-like fibrous stroma.

An endocrine gland neoplasm is a neoplasm affecting one or more glands of the endocrine system.

Examples include:

- Adrenal tumor

- Pituitary adenoma

The most common form is thyroid cancer.

Condition such as pancreatic cancer or ovarian cancer can be considered endocrine tumors, or classified under other systems.

Pinealoma is often grouped with brain tumors because of its location.

Adrenocortical carcinoma (ACC, adrenal cortical carcinoma, adrenal cortical cancer, adrenal cortex cancer, etc.) is an aggressive cancer originating in the cortex (steroid hormone-producing tissue) of the adrenal gland. Adrenocortical carcinoma is a rare tumor, with incidence of 1–2 per million population annually. Adrenocortical carcinoma has a bimodal distribution by age, with cases clustering in children under 5, and in adults 30–40 years old. Adrenocortical carcinoma is remarkable for the many hormonal syndromes which can occur in patients with steroid hormone-producing ("functional") tumors, including Cushing's syndrome, Conn syndrome, virilization, and feminization. Adrenocortical carcinoma has often invaded nearby tissues or metastasized to distant organs at the time of diagnosis, and the overall 5-year survival rate is only 20–35%. The widely used angiotensin-II-responsive steroid-producing cell line H295R was originally isolated from a tumor diagnosed as adrenocortical carcinoma.

Multiple endocrine neoplasia type 2B (also known as "MEN2B", "Mucosal neuromata with endocrine tumors", "Multiple endocrine neoplasia type 3", and "Wagenmann–Froboese syndrome") is a genetic disease that causes multiple tumors on the mouth, eyes, and endocrine glands. It is the most severe type of multiple endocrine neoplasia, differentiated by the presence of benign oral and submucosal tumors in addition to endocrine malignancies. It was first described by Wagenmann in 1922, and was first recognized as a syndrome in 1965-1966 by E.D. Williams and D.J. Pollock.

MEN 2B typically manifests before a child is 10 years old. Affected individuals tend to be tall and lanky, with an elongated face and protruding, blubbery lips. Benign tumors (neoplasms) develop in the mouth, eyes, and submucosa of almost all organs in the first decade of life.

Medullary thyroid cancer almost always occurs, sometimes in infancy. It is often aggressive. Cancer of the adrenal glands (pheochromocytoma) occurs in 50% of cases.

A variety of eponyms have been proposed for MEN 2B, such as Williams-Pollock syndrome, Gorlin-Vickers syndrome, and Wagenmann-Froboese syndrome. However, none ever gained sufficient traction to merit continued use, and are no longer used in the medical literature.

The prevalence of MEN2B is not well established, but has been derived from other epidemiological considerations as 1 in 600,000 to 1 in 4,000,000. The annual incidence has been estimated at 4 per 100 million per year.

An adrenal tumor or adrenal mass is any benign or malignant neoplasms of the adrenal gland, several of which are notable for their tendency to overproduce endocrine hormones. Adrenal cancer is the presence of malignant adrenal tumors, and includes neuroblastoma, adrenocortical carcinoma and some adrenal pheochromocytomas. Most adrenal pheochromocytomas and all adrenocortical adenomas are benign tumors, which do not metastasize or invade nearby tissues, but may cause significant health problems by unbalancing hormones.

The signs and symptoms of a pheochromocytoma are those of sympathetic nervous system hyperactivity, including:

- Skin sensations

- Flank pain

- Elevated heart rate

- Elevated blood pressure, including paroxysmal (sporadic, episodic) high blood pressure, which sometimes can be more difficult to detect; another clue to the presence of pheochromocytoma is orthostatic hypotension (a fall in systolic blood pressure greater than 20 mmHg or a fall in diastolic blood pressure greater than 10 mmHg upon standing)

- Palpitations

- Anxiety often resembling that of a panic attack

- Diaphoresis (excessive sweating)

- Headaches – most common symptom

- Pallor

- Weight loss

- Localized amyloid deposits found microscopically

- Elevated blood glucose level (due primarily to catecholamine stimulation of lipolysis (breakdown of stored fat) leading to high levels of free fatty acids and the subsequent inhibition of glucose uptake by muscle cells. Further, stimulation of beta-adrenergic receptors leads to glycogenolysis and gluconeogenesis and thus elevation of blood glucose levels).

A pheochromocytoma can also cause resistant arterial hypertension. A pheochromocytoma can be fatal if it causes a hypertensive emergency, that is, severely high blood pressure that impairs one or more organ systems (formerly called "malignant hypertension"). This hypertension is not well controlled with standard blood pressure medications.

Not all patients experience all of the signs and symptoms listed. The most common presentation is headache, excessive sweating, and increased heart rate, with the attack subsiding in less than one hour.

Tumors may grow large, but most are smaller than .

An adenoma of a parathyroid gland may secrete inappropriately high amounts of parathyroid hormone and thereby cause primary hyperparathyroidism.

A adrenocortical adenoma (or adrenal cortical adenoma, or sometimes simply adrenal adenoma) is a benign tumor of the adrenal cortex.

It can present with Cushing's syndrome or primary aldosteronism. They may also secrete androgens, causing hyperandrogenism. Also, they are often diagnosed incidentally as incidentalomas.

Is a well circumscribed, yellow tumour in the adrenal cortex, which is usually 2–5 cm in diameter. The color of the tumour, as with adrenal cortex as a whole, is due to the stored lipid (mainly cholesterol), from which the cortical hormones are synthesized. These tumors are frequent incidental findings at post mortem examination, and appear to have produced no significant metabolic disorder; only a very small percentage lead to Cushing's syndrome. Nevertheless, these apparently non-functioning adenomas are most often encountered in elder obese people. There is some debate that they may really represent nodules in diffuse nodular cortical hyperplasia.

Very occasionally, a true adrenal cortical adenoma is associated with the clinical manifestations of Conn's syndrome, and can be shown to be excreting mineralocorticoids.

The adrenal cortex is composed of three distinct layers of endocrine cells which produce critical steroid hormones. These include the glucocorticoids which are critical for regulation of blood sugar and the immune system, as well as response to physiological stress, the mineralcorticoid aldosterone, which regulates blood pressure and kidney function, and certain sex hormones. Both benign and malignant tumors of the adrenal cortex may produce steroid hormones, with important clinical consequences.

Pheochromocytoma (PCC) is a neuroendocrine tumor of the medulla of the adrenal glands (originating in the chromaffin cells), or extra-adrenal chromaffin tissue that failed to involute after birth, that secretes high amounts of catecholamines, mostly norepinephrine, plus epinephrine to a lesser extent. Extra-adrenal paragangliomas (often described as extra-adrenal pheochromocytomas) are closely related, though less common, tumors that originate in the ganglia of the sympathetic nervous system and are named based upon the primary anatomical site of origin. The term is from Greek "phaios" "dark", "chroma" "color", "kytos" "cell", "-oma" "tumor".

Pituitary adenomas are seen in 10% of neurological patients. A lot of them remain undiagnosed. Treatment is usually surgical, to which patients generally respond well. The most common subtype, prolactinoma, is seen more often in women, and is frequently diagnosed during pregnancy as the hormone progesterone increases its growth. Medical therapy with cabergoline or bromocriptine generally suppresses prolactinomas; progesterone antagonist therapy has not proven to be successful.

About 85% of paragangliomas develop in the abdomen; only 12% develop in the chest and 3% in the head and neck region (the latter are the most likely to be symptomatic). While most are single, rare multiple cases occur (usually in a hereditary syndrome). Paragangliomas are described by their site of origin and are often given special names:

- Carotid paraganglioma (carotid body tumor): Is the most common of the head and neck paragangliomas. It usually presents as a painless neck mass, but larger tumors may cause cranial nerve palsies, usually of the vagus nerve and hypoglossal nerve.

- Organ of Zuckerkandl: A collection of paraganglia near the bifurcation of the aorta, comprising a small mass of neural crest-derived chromaffin cells. Serves as a common origin of abdominal paragangliomas.

- Glomus tympanicum and Glomus jugulare: Both commonly present as a middle ear mass resulting in tinnitus (in 80%) and hearing loss (in 60%). The cranial nerves of the jugular foramen may be compressed, resulting swallowing difficulty, or ipsilateral weakness of the upper trapezius and sternocleiodomastoid muscles (from compression of the spinal accessory nerve). These patients present with a reddish bulge behind an intact ear drum. This condition is also known as the "Red drum". On application of pressure to the external ear canal with the help of a pneumatic ear speculum the mass could be seen to blanch. This sign is known as "Brown's sign". A deficient bony plate along the tympanic portion of the internal carotid artery (aberrant ICA) is a normal variant and can be mistaken with glomus jugulare.

- Vagal paraganglioma: These are the least common of the head and neck paragangliomas. They usually present as a painless neck mass, but may result in dysphagia and hoarseness.

- Pulmonary paraganglioma: These occur in the lung and may be either single or multiple.

- Other sites: Rare sites of involvement are the larynx, nasal cavity, paranasal sinuses, thyroid gland, and the thoracic inlet, as well as the bladder in extremely rare cases.

Most paragangliomas are either asymptomatic or present as a painless mass. While all contain neurosecretory granules, only in 1–3% of cases is secretion of hormones such as catecholamines abundant enough to be clinically significant; in that case manifestations often resemble those of pheochromocytomas (intra-medullary paraganglioma).

The majority of myelolipomas are asymptomatic. Most do not produce any adrenal hormones. Most are only discovered as a result of investigation for another problem.

When myelolipomas do produce symptoms, it is usually because they have become large, and are pressing on other organs or tissues nearby. Symptoms include pain in the abdomen or , blood in the urine, a palpable lump or high blood pressure.

As they are benign tumors, myelolipomas do not spread to other body parts. Larger myelolipomas are at risk of localised tissue death and bleeding, which may cause a retroperitoneal haemorrhage.

Hyperplasia (from ancient Greek ὑπέρ "huper", "over" + πλάσις "plasis", "formation"), or hypergenesis, is an increase in the amount of organic tissue that results from cell proliferation. It may lead to the gross enlargement of an organ and the term is sometimes confused with benign neoplasia or benign tumor.

Hyperplasia is a common preneoplastic response to stimulus. Microscopically, cells resemble normal cells but are increased in numbers. Sometimes cells may also be increased in size (hypertrophy). Hyperplasia is different from hypertrophy in that the adaptive cell change in hypertrophy is an increase in the "size" of cells, whereas hyperplasia involves an increase in the "number" of cells.

Hyperplasia is considered to be a physiological (normal) response to a specific stimulus, and the cells of a hyperplastic growth remain subject to normal regulatory control mechanisms. However, hyperplasia can also occur as a pathological response, if an excess of hormone or growth factor is responsible for the stimuli. Similarly to physiological hyperplasia, cells that undergo pathologic hyperplasia are controlled by growth hormones, and cease to proliferate if such stimuli are removed. This differs from neoplasia (the process underlying cancer and benign tumors), in which genetically abnormal cells manage to proliferate in a non-physiological manner which is unresponsive to normal stimuli. That being said, the effects caused by pathologic hyperplasia can provide a suitable foundation from which neoplastic cells may develop.

Myelolipoma ("myelo-", from the ancient greek "μυελός", marrow; "lipo", meaning "of, or pertaining to, fat; "-oma", meaning tumor or mass") is a benign tumor-like lesion composed of mature adipose (fat) tissue and haematopoietic (blood-forming) elements in various proportions.

Myelolipomas can present in the adrenal gland, or outside of the gland.

The following diseases manifest by means of endocrine dysfunction: Cushing syndrome, syndrome of inappropriate antidiuretic hormone, hypercalcemia, hypoglycemia, carcinoid syndrome, and hyperaldosteronism.

The following diseases manifest by means of neurological dysfunction: Lambert-Eaton myasthenic syndrome, paraneoplastic cerebellar degeneration, encephalomyelitis, limbic encephalitis, brainstem encephalitis, opsoclonus myoclonus ataxia syndrome, anti-NMDA receptor encephalitis, and polymyositis.

Adrenal gland disorders (or diseases) are conditions that interfere with the normal functioning of the adrenal glands. Adrenal disorders may cause hyperfunction or hypofunction, and may be congenital or acquired.

The adrenal gland produces hormones that affects growth, development and stress, and also helps to regulate kidney function. There are two parts of the adrenal glands, the adrenal cortex and the adrenal medulla. The adrenal cortex produces mineralocorticoids, which regulate salt and water balance within the body, glucocorticoids (including cortisol) which have a wide number of roles within the body, and androgens, hormones with testosterone-like function. The adrenal medulla produces epinephrine (adrenaline) and norepinephrine (noradrenaline). Disorders of the adrenal gland may affect the production of one or more of these hormones.

The first symptoms of neuroblastoma are often vague making diagnosis difficult. Fatigue, loss of appetite, fever, and joint pain are common. Symptoms depend on primary tumor locations and metastases if present:

- In the abdomen, a tumor may cause a swollen belly and constipation.

- A tumor in the chest may cause breathing problems.

- A tumor pressing on the spinal cord may cause weakness and thus an inability to stand, crawl, or walk.

- Bone lesions in the legs and hips may cause pain and limping.

- A tumor in the bones around the eyes or orbits may cause distinct bruising and swelling.

- Infiltration of the bone marrow may cause pallor from anemia.

Neuroblastoma often spreads to other parts of the body before any symptoms are apparent and 50 to 60% of all neuroblastoma cases present with metastases.

The most common location for neuroblastoma to originate (i.e., the primary tumor) is in the adrenal glands. This occurs in 40% of localized tumors and in 60% of cases of widespread disease. Neuroblastoma can also develop anywhere along the sympathetic nervous system chain from the neck to the pelvis. Frequencies in different locations include: neck (1%), chest (19%), abdomen (30% non-adrenal), or pelvis (1%). In rare cases, no primary tumor can be discerned.

Rare but characteristic presentations include transverse myelopathy (tumor spinal cord compression, 5% of cases), treatment-resistant diarrhea (tumor vasoactive intestinal peptide secretion, 4% of cases), Horner's syndrome (cervical tumor, 2.4% of cases), opsoclonus myoclonus syndrome and ataxia (suspected paraneoplastic cause, 1.3% of cases), and hypertension (catecholamine secretion or renal artery compression, 1.3% of cases).

Most affected cats present with muscular weakness and/or ocular signs of hypertension. Signs of muscle weakness can include a plantigrade stance of the hindlimbs, cervical ventroflexion, inability to jump, lateral recumbency, or collapse. Ocular signs of arterial hypertension include mydriasis, hyphema, or blindness due to retinal detachment and/or intraocular hemorrhages. A palpable mass in the cranial abdomen is another potential finding.

People often have few or no symptoms. They may get occasional muscular weakness, muscle spasms, tingling sensations, or excessive urination.

High blood pressure, manifestations of muscle cramps (due to hyperexcitability of neurons secondary to low blood calcium), muscle weakness (due to hypoexcitability of skeletal muscles secondary to hypokalemia), and headaches (due to low blood potassium or high blood pressure) may be seen.

Secondary hyperaldosteronism is often related to decreased cardiac output which is associated with elevated renin levels.

Signs and symptoms include: hypoglycemia, dehydration, weight loss, and disorientation. Additional signs and symptoms include weakness, tiredness, dizziness, low blood pressure that falls further when standing (orthostatic hypotension), cardiovascular collapse, muscle aches, nausea, vomiting, and diarrhea. These problems may develop gradually and insidiously. Addison's disease can present with tanning of the skin that may be patchy or even all over the body. Characteristic sites of tanning are skin creases (e.g. of the hands) and the inside of the cheek (buccal mucosa). Goitre and vitiligo may also be present. Eosinophilia may also occur.